return package lost claim

Hello,

@Dougal_Amazon

We recently have a issue with return shipment. After customer drop off the return package, the return package(amazon prepaid label) lost in transit. Buyer initiate A-to-Z claim and get the full refund back. We appeal on A-to-z decision but amazon still think we are responsible for lost package. We do initiate a UPS lost package claim. UPS grant the claim and reimbursed shipper (amazon). However, we still get nothing back. We are requesting the refund for that package lost. We submit a case number to amazon. Please escalate this case.